Do I need any additional r-b for this to get in? Thxs, Håkon > On 26 Jun 2017, at 11:40, jackm <jackm@xxxxxxxxxxxxxxxxxx> wrote: > > Nice catch, Haakon! > > -Jack > > On Tue, 20 Jun 2017 14:07:50 +0200 > Håkon Bugge <Haakon.Bugge@xxxxxxxxxx> wrote: > >> CM REQs cannot be successfully retried, because a new pv_cm_id is >> created for each request, without checking if one already exists. >> >> By checking if an id exists before creating one, the bug is fixed. >> >> This bug can be provoked by running an RDMA CM user-land application, >> but inserting a five seconds delay before the rdma_accept() call on >> the passive side. This delay is larger than the default CMA timeout, >> and triggers a retry from the active side. The retried REQ will use >> another pv_cm_id (the cm_id on the wire). This confuses the CM >> protocol and two REJs are sent from the passive side. >> >> Here is an excerpt from ibdump running without the patch: >> >> 3.285092 LID: 4 -> LID: 4 SDP 290 CM: ConnectRequest(SDP >> Hello) 7.382711 LID: 4 -> LID: 4 SDP 290 CM: >> ConnectRequest(SDP Hello) 7.382861 LID: 4 -> LID: 4 >> InfiniBand 290 CM: ConnectReject 7.387644 LID: 4 -> LID: >> 4 InfiniBand 290 CM: ConnectReject >> >> and here is the same with bug fix applied: >> >> 3.251010 LID: 4 -> LID: 4 SDP 290 CM: ConnectRequest(SDP >> Hello) 7.349387 LID: 4 -> LID: 4 SDP 290 CM: >> ConnectRequest(SDP Hello) 8.258443 LID: 4 -> LID: 4 SDP >> 290 CM: ConnectReply(SDP Hello) 8.259890 LID: 4 -> LID: 4 >> InfiniBand 290 CM: ReadyToUse >> >> Suggested-by: Venkat Venkatsubra <venkat.x.venkatsubra@xxxxxxxxxx> >> Signed-off-by: Håkon Bugge <haakon.bugge@xxxxxxxxxx> >> Reported-by: Wei Lin Guay <wei.lin.guay@xxxxxxxxxx> >> Tested-by: Wei Lin Guay <wei.lin.guay@xxxxxxxxxx> >> Reviewed-by: Yuval Shaia <yuval.shaia@xxxxxxxxxx> > > Acked-by: Jack Morgenstein <jackm@xxxxxxxxxxxxxxxxxx> > -- > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
